Near-Relativistic Electron Beam Production Using a Pyroelectric Crystal Array

Laser-powered acceleration structures such as dielectric laser accelerators (DLAs) require injection of a sub-micron-scale electron bunch to achieve high-quality, monoenergetic output beams. Field emission from an array of nanotips, followed by further acceleration and focusing, is a promising approach to achieving the requisite small beam sizes and near-relativistic energies for successful injection; however, conventional high-voltage sources are not easily integrated into dielectric structures. We have demonstrated that the strong electrostatic fields produced by pyroelectric crystals during heating and cooling can be used for field emission and pre-acceleration. We present a design, and proof-of-principle experimental results, for a low-energy injection module based on emission from nanotips within a hollow channel along the axis of a lithium niobate crystal. This mechanism is stageable and is predicted to deliver energies of several hundred keV in a few centimeters, suitable e.g. for DLA injection as well as potentially useful for industrial or medical applications.